Get Count Occurrences of substring in string

gistfile1.txt

   /// <summary>
        /// Gets the count of substrings in the string
        /// </summary>
        /// <param name="text"></param>
        /// <param name="substring"></param>
        /// <returns></returns>
        public static int GetCount(this string text, string substring)
        {
            int count = 0;
            var span = text.AsSpan();
            var len = substring.Length;
            for (int i = 0; i <= span.Length - len; i++)
            {
                var slice = span.Slice(i, len);
                if (slice.Equals(substring, StringComparison.Ordinal))
                    count++;
            }
            return count;
        }